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Structural formula
Structural formula of monoethanolamine
Surname Monoethanolamine
other names
  • 2-aminoethan-1-ol ( IUPAC )
  • Ethanolamine (simplified)
  • Aminoethanol
  • Colamin
  • Olamine ( INN )
  • beta-hydroxyethylamine
Molecular formula C 2 H 7 NO
Brief description

colorless, oily liquid with an ammonia- like odor

External identifiers / databases
CAS number 141-43-5
EC number 205-483-3
ECHA InfoCard 100,004,986
PubChem 700
ChemSpider 13835336
DrugBank DB03994
Wikidata Q410387
Molar mass 61.08 g mol −1
Physical state



1.02 g cm −3 (20 ° C)

Melting point

10 ° C

boiling point

172 ° C

Vapor pressure
  • 0.5 h Pa (20 ° C)
  • 1.63 hPa (40 ° C)
  • 3.43 hPa (50 ° C)
pK s value


  • miscible with water
  • miscible with alcohols
Refractive index

1.4541 (20 ° C)

safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary
05 - Corrosive 07 - Warning


H and P phrases H: 302-312-332-314-335-412
P: 261-273-301 + 312 + 330-303 + 361 + 353-304 + 340 + 310-305 + 351 + 338
  • DFG : 0.2 ml m −3 , 0.51 mg m −3
  • Switzerland: 2 ml m −3 or 5 mg m −3
Toxicological data
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Monoethanolamine (according to IUPAC nomenclature: 2-aminoethan-1-ol , also referred to as MEA for short ) is an organic-chemical compound from the group of amino alcohols . It is their simplest representative and is used as a raw material in the chemical industry .


Monoethanolamine is the biogenic amine of the amino acid serine . Ethanolamines occur as a polar head group in phosphatidylethanolamine , which belongs to the group of phospholipids . Phospholipids essentially form the lipid bilayer in cell membranes . This polar head group can also be found in endocannabinoids .

Extraction and presentation

Monoethanolamine is produced on an industrial scale by reacting ethylene oxide with ammonia at temperatures of 60-130 ° C. and pressures of 70-160 bar in the presence of water and an acidic catalyst . Acidic zeolites (for example aluminosilicates ) or organic ion exchange resins in the H form (protons) are particularly preferably used.

Conversion of ethylene oxide with ammonia to monoethanolamine in the presence of water and an acidic ion exchange resin as a catalyst

The higher ethanolamines, especially diethanolamine and triethanolamine, are produced as by-products . The proportion of monoethanolamine can be greatly increased by an excess of ammonia. The molar ratio of ammonia to ethylene oxide is therefore preferably 20: 7. The complete reaction preferably takes place in stirred tank or tubular reactors. The reaction mixture is purified and worked up by multi-stage distillation in rectification columns .


Physical Properties

Monoethanolamine has a relative gas density of 2.11 (density ratio to dry air at the same temperature and pressure ) and a relative density of the vapor-air mixture of 1.00 (density ratio to dry air at 20 ° C and normal pressure ). In addition, ethanolamine has a vapor pressure of 0.50 hPa at 20 ° C, 1.63 hPa at 40 ° C and 3.43 hPa at 50 ° C.

Chemical properties

Monoethanolamine is a difficult to ignite liquid from the group of amino alcohols . It can be mixed with water and many alcohols . Furthermore, ethanolamine is hygroscopic and absorbs water vapor and carbon dioxide . The liquid is difficult or very difficult to volatilize. The substance can polymerize on contact with acrolein or acrylic acid . In addition, monoethanolamine reacts strongly with oxidizing agents and acids as well as iron- sulfur compounds . An aqueous solution of concentration 100 g / l at 20 ° C has a pH of 12.1. As a result, solutions of monoethanolamine are strongly alkaline .


Monoethanolamine is used:

safety instructions

Monoethanolamine is a difficult to ignite liquid . The vapors can form explosive mixtures with air when the substance is heated above its flash point . The substance is mainly absorbed through the respiratory tract and skin . This can range from slight irritation to severe burns of the mucous membranes and skin. Furthermore, a skin-sensitizing effect was found. Chronic consequences can be skin changes . The ignition temperature is 410 ° C. The substance therefore falls into temperature class T2 and explosion group IIA. With a flash point of 85 ° C, monoethanolamine is considered to be relatively flame-retardant.

Risk assessment

Monoethanolamine was included by the EU in 2012 in accordance with Regulation (EC) No. 1907/2006 (REACH) in the context of substance evaluation in the Community's ongoing action plan ( CoRAP ). The effects of the substance on human health and the environment are re-evaluated and, if necessary, follow-up measures are initiated. The reasons for the uptake of monoethanolamine were concerns about high (aggregated) tonnage and widespread use, as well as the possible risk of sensitizing properties. The re-evaluation started in 2014 and was carried out by the United Kingdom . A final report was then published.

Related links

Individual evidence

  1. a b c d e f g h i j k l m n o p q Entry on 2-aminoethanol in the GESTIS substance database of the IFA , accessed on March 3, 2019 (JavaScript required)
  2. ^ Hall, HK, J. Am. Chem. Soc. , 1957 , 79 , 5441.
  3. a b entry on aminoethanols. In: Römpp Online . Georg Thieme Verlag, accessed on March 3, 2019.
  4. Entry on 2-aminoethanol in the Hazardous Substances Data Bank , accessed on March 3, 2019.
  5. Entry on 2-aminoethanol in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on March 3, 2019. Manufacturers or distributors can expand the harmonized classification and labeling .
  6. Swiss Accident Insurance Fund (Suva): Limit values ​​- current MAK and BAT values (search for 141-43-5 or 2-aminoethanol ), accessed on September 14, 2019.
  7. a b Patent EP1289927B1 : Process for the production of ethanolamines. Published on May 14, 2014 , applicant: BASF SE, inventor: Matthias Frauenkron, Ulrich Müller, Wolfgang Harder, Jörg Unger, Johann-Peter Melder, Anton Meier, Walter Himmel.
  8. Patent DE971375 : Process for the production of an alkaline, soap-free, reactive fluorine in addition to calcium carbonate containing toothpaste. Registered on August 26, 1951 , published on January 15, 1959 , applicant: Knoll AG , inventor: Oskar Eichler , Kurt Kraft, Philipp Zut.
  9. German Dental Journal, Vol. 7, pp. 702 & 708 (1952)
  10. Klaus Weissermel , Hans-Jürgen Arpe , Charlet R. Lindley, Stephen Hawkins: Chap. 7. Oxidation Products of Ethylene . In: Industrial Organic Chemistry . Wiley-VCH , 2003, ISBN 3-527-30578-5 , pp. 159-161.
  11. ^ European Chemicals Agency (ECHA): Substance Evaluation Report and Conclusion Document .
  12. Community rolling action plan ( CoRAP ) of the European Chemicals Agency (ECHA): 2-aminoethanol , accessed on March 26, 2019.